title: Controlled insertional mutagenesis using a LINE-1 (ORFeus) gene-trap mouse model.
abstract: A codon-optimized mouse LINE-1 element, ORFeus, exhibits dramatically higher retrotransposition frequencies compared with its native long interspersed element 1 counterpart. To establish a retrotransposon-mediated mouse model with regulatable and potent mutagenic capabilities, we generated a tetracycline (tet)-regulated ORFeus element harboring a gene-trap cassette. Here, we show that mice expressing tet-ORFeus broadly exhibit robust retrotransposition in somatic tissues when treated with doxycycline. Consistent with a significant mutagenic burden, we observed a reduced number of double transgenic animals when treated with high-level doxycycline during embryogenesis. Transgene induction in skin resulted in a white spotting phenotype due to somatic ORFeus-mediated mutations that likely disrupt melanocyte development. The data suggest a high level of transposition in melanocyte precursors and consequent mutation of genes important for melanoblast proliferation, differentiation, or migration. These findings reveal the utility of a retrotransposon-based mutagenesis system as an alternative to existing DNA transposon systems. Moreover, breeding these mice to different tet-transactivator/reversible tet-transactivator lines supports broad functionality of tet-ORFeus because of the potential for dose-dependent, tissue-specific, and temporal-specific mutagenesis.
authors.affiliation: Department of Molecular Biology and Genetics, and High Throughput Biology Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. kathryn.odonnell@UTSouthwestern.edu
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: O'Donnell
authors.forename: Wenfeng
authors.initials: W
authors.lastname: An
authors.forename: Christina T
authors.initials: CT
authors.lastname: Schrum
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Wheelan
authors.forename: Jef D
authors.initials: JD
authors.lastname: Boeke
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D017931:DNA Primers / Q000235:genetics; D005455:Fluorescent Antibody Technique; D005838:Genotype; D006367:HeLa Cells; D006801:Humans; D020084:Long Interspersed Nucleotide Elements / Q000235:genetics*; D008544:Melanocytes / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D016254:Mutagenesis, Insertional / Q000379:methods*; D016133:Polymerase Chain Reaction; D060888:Real-Time Polymerase Chain Reaction; D018626:Retroelements / Q000235:genetics*; D013752:Tetracycline
chemical_list: D017931:DNA Primers; D018626:Retroelements; D013752:Tetracycline
keywords: L1 retrotransposon; mus musculus; tet-promoter; white-spotted phenotype